The present invention relates to an improved diaphragm pump for pumping pressurized liquid and more particularly concerns such a pump of enhanced durability, increased output pressure, and increased freedom from leakage.
Pressurized discharge of various types of liquid insecticides, fertilizers, and other garden-type treatment liquids, has been accomplished by directly pressurizing a liquid container itself and controlling discharge of liquid from the pressurized container by means of a manually controlled nozzle valve. For all but the smallest of such liquid spraying containers, it is difficult and time consuming to produce sufficient pressure within the relatively large volume of the container as is required for adequate liquid dispensing. The large pressurized volume also makes it more difficult to obtain those higher pressures required for projecting the liquid stream with sufficient power to provide an increased spraying range, or an increased force of impact of the sprayed stream.
In many such prior art sprayers, damage, wear or failure of the pumping mechanism is difficult to repair, and the entire apparatus often must be replaced upon failure of the pump. Piston-type pumping mechanisms are prone to failure and subject to relatively rapid wear, resulting in early loss of pumping power and leakage.
Diaphragm operated pumps have not been applied to garden-type sprayers. Moreover, diaphragm pumps employed in other applications are relatively complex and expensive, are difficult to manufacture and assemble, and require uniquely arranged and complicated linear drive mechanisms.
Accordingly, it is an object of the present invention to provide a diaphragm pump that avoids or minimizes above-mentioned problems.